v4.19.13 snapshot.
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
new file mode 100644
index 0000000..6344f1b
--- /dev/null
+++ b/net/dccp/ipv6.c
@@ -0,0 +1,1169 @@
+/*
+ * DCCP over IPv6
+ * Linux INET6 implementation
+ *
+ * Based on net/dccp6/ipv6.c
+ *
+ * Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/xfrm.h>
+#include <linux/string.h>
+
+#include <net/addrconf.h>
+#include <net/inet_common.h>
+#include <net/inet_hashtables.h>
+#include <net/inet_sock.h>
+#include <net/inet6_connection_sock.h>
+#include <net/inet6_hashtables.h>
+#include <net/ip6_route.h>
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/ip6_checksum.h>
+#include <net/xfrm.h>
+#include <net/secure_seq.h>
+#include <net/sock.h>
+
+#include "dccp.h"
+#include "ipv6.h"
+#include "feat.h"
+
+/* The per-net dccp.v6_ctl_sk is used for sending RSTs and ACKs */
+
+static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
+static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
+
+/* add pseudo-header to DCCP checksum stored in skb->csum */
+static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
+ const struct in6_addr *saddr,
+ const struct in6_addr *daddr)
+{
+ return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
+}
+
+static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct dccp_hdr *dh = dccp_hdr(skb);
+
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
+}
+
+static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
+{
+ return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
+ ipv6_hdr(skb)->saddr.s6_addr32,
+ dccp_hdr(skb)->dccph_dport,
+ dccp_hdr(skb)->dccph_sport );
+
+}
+
+static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
+ const struct dccp_hdr *dh;
+ struct dccp_sock *dp;
+ struct ipv6_pinfo *np;
+ struct sock *sk;
+ int err;
+ __u64 seq;
+ struct net *net = dev_net(skb->dev);
+
+ /* Only need dccph_dport & dccph_sport which are the first
+ * 4 bytes in dccp header.
+ * Our caller (icmpv6_notify()) already pulled 8 bytes for us.
+ */
+ BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8);
+ BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8);
+ dh = (struct dccp_hdr *)(skb->data + offset);
+
+ sk = __inet6_lookup_established(net, &dccp_hashinfo,
+ &hdr->daddr, dh->dccph_dport,
+ &hdr->saddr, ntohs(dh->dccph_sport),
+ inet6_iif(skb), 0);
+
+ if (!sk) {
+ __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
+ ICMP6_MIB_INERRORS);
+ return;
+ }
+
+ if (sk->sk_state == DCCP_TIME_WAIT) {
+ inet_twsk_put(inet_twsk(sk));
+ return;
+ }
+ seq = dccp_hdr_seq(dh);
+ if (sk->sk_state == DCCP_NEW_SYN_RECV)
+ return dccp_req_err(sk, seq);
+
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk))
+ __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
+
+ if (sk->sk_state == DCCP_CLOSED)
+ goto out;
+
+ dp = dccp_sk(sk);
+ if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
+ !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
+ __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
+ goto out;
+ }
+
+ np = inet6_sk(sk);
+
+ if (type == NDISC_REDIRECT) {
+ if (!sock_owned_by_user(sk)) {
+ struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
+
+ if (dst)
+ dst->ops->redirect(dst, sk, skb);
+ }
+ goto out;
+ }
+
+ if (type == ICMPV6_PKT_TOOBIG) {
+ struct dst_entry *dst = NULL;
+
+ if (!ip6_sk_accept_pmtu(sk))
+ goto out;
+
+ if (sock_owned_by_user(sk))
+ goto out;
+ if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
+ goto out;
+
+ dst = inet6_csk_update_pmtu(sk, ntohl(info));
+ if (!dst)
+ goto out;
+
+ if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
+ dccp_sync_mss(sk, dst_mtu(dst));
+ goto out;
+ }
+
+ icmpv6_err_convert(type, code, &err);
+
+ /* Might be for an request_sock */
+ switch (sk->sk_state) {
+ case DCCP_REQUESTING:
+ case DCCP_RESPOND: /* Cannot happen.
+ It can, it SYNs are crossed. --ANK */
+ if (!sock_owned_by_user(sk)) {
+ __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
+ sk->sk_err = err;
+ /*
+ * Wake people up to see the error
+ * (see connect in sock.c)
+ */
+ sk->sk_error_report(sk);
+ dccp_done(sk);
+ } else
+ sk->sk_err_soft = err;
+ goto out;
+ }
+
+ if (!sock_owned_by_user(sk) && np->recverr) {
+ sk->sk_err = err;
+ sk->sk_error_report(sk);
+ } else
+ sk->sk_err_soft = err;
+
+out:
+ bh_unlock_sock(sk);
+ sock_put(sk);
+}
+
+
+static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct sk_buff *skb;
+ struct in6_addr *final_p, final;
+ struct flowi6 fl6;
+ int err = -1;
+ struct dst_entry *dst;
+
+ memset(&fl6, 0, sizeof(fl6));
+ fl6.flowi6_proto = IPPROTO_DCCP;
+ fl6.daddr = ireq->ir_v6_rmt_addr;
+ fl6.saddr = ireq->ir_v6_loc_addr;
+ fl6.flowlabel = 0;
+ fl6.flowi6_oif = ireq->ir_iif;
+ fl6.fl6_dport = ireq->ir_rmt_port;
+ fl6.fl6_sport = htons(ireq->ir_num);
+ security_req_classify_flow(req, flowi6_to_flowi(&fl6));
+
+
+ rcu_read_lock();
+ final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
+ rcu_read_unlock();
+
+ dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
+ if (IS_ERR(dst)) {
+ err = PTR_ERR(dst);
+ dst = NULL;
+ goto done;
+ }
+
+ skb = dccp_make_response(sk, dst, req);
+ if (skb != NULL) {
+ struct dccp_hdr *dh = dccp_hdr(skb);
+ struct ipv6_txoptions *opt;
+
+ dh->dccph_checksum = dccp_v6_csum_finish(skb,
+ &ireq->ir_v6_loc_addr,
+ &ireq->ir_v6_rmt_addr);
+ fl6.daddr = ireq->ir_v6_rmt_addr;
+ rcu_read_lock();
+ opt = ireq->ipv6_opt;
+ if (!opt)
+ opt = rcu_dereference(np->opt);
+ err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass);
+ rcu_read_unlock();
+ err = net_xmit_eval(err);
+ }
+
+done:
+ dst_release(dst);
+ return err;
+}
+
+static void dccp_v6_reqsk_destructor(struct request_sock *req)
+{
+ dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
+ kfree(inet_rsk(req)->ipv6_opt);
+ kfree_skb(inet_rsk(req)->pktopts);
+}
+
+static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
+{
+ const struct ipv6hdr *rxip6h;
+ struct sk_buff *skb;
+ struct flowi6 fl6;
+ struct net *net = dev_net(skb_dst(rxskb)->dev);
+ struct sock *ctl_sk = net->dccp.v6_ctl_sk;
+ struct dst_entry *dst;
+
+ if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
+ return;
+
+ if (!ipv6_unicast_destination(rxskb))
+ return;
+
+ skb = dccp_ctl_make_reset(ctl_sk, rxskb);
+ if (skb == NULL)
+ return;
+
+ rxip6h = ipv6_hdr(rxskb);
+ dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
+ &rxip6h->daddr);
+
+ memset(&fl6, 0, sizeof(fl6));
+ fl6.daddr = rxip6h->saddr;
+ fl6.saddr = rxip6h->daddr;
+
+ fl6.flowi6_proto = IPPROTO_DCCP;
+ fl6.flowi6_oif = inet6_iif(rxskb);
+ fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
+ fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
+ security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
+
+ /* sk = NULL, but it is safe for now. RST socket required. */
+ dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
+ if (!IS_ERR(dst)) {
+ skb_dst_set(skb, dst);
+ ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0);
+ DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
+ DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
+ return;
+ }
+
+ kfree_skb(skb);
+}
+
+static struct request_sock_ops dccp6_request_sock_ops = {
+ .family = AF_INET6,
+ .obj_size = sizeof(struct dccp6_request_sock),
+ .rtx_syn_ack = dccp_v6_send_response,
+ .send_ack = dccp_reqsk_send_ack,
+ .destructor = dccp_v6_reqsk_destructor,
+ .send_reset = dccp_v6_ctl_send_reset,
+ .syn_ack_timeout = dccp_syn_ack_timeout,
+};
+
+static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
+{
+ struct request_sock *req;
+ struct dccp_request_sock *dreq;
+ struct inet_request_sock *ireq;
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
+ struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
+
+ if (skb->protocol == htons(ETH_P_IP))
+ return dccp_v4_conn_request(sk, skb);
+
+ if (!ipv6_unicast_destination(skb))
+ return 0; /* discard, don't send a reset here */
+
+ if (dccp_bad_service_code(sk, service)) {
+ dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
+ goto drop;
+ }
+ /*
+ * There are no SYN attacks on IPv6, yet...
+ */
+ dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
+ if (inet_csk_reqsk_queue_is_full(sk))
+ goto drop;
+
+ if (sk_acceptq_is_full(sk))
+ goto drop;
+
+ req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
+ if (req == NULL)
+ goto drop;
+
+ if (dccp_reqsk_init(req, dccp_sk(sk), skb))
+ goto drop_and_free;
+
+ dreq = dccp_rsk(req);
+ if (dccp_parse_options(sk, dreq, skb))
+ goto drop_and_free;
+
+ if (security_inet_conn_request(sk, skb, req))
+ goto drop_and_free;
+
+ ireq = inet_rsk(req);
+ ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
+ ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
+ ireq->ireq_family = AF_INET6;
+ ireq->ir_mark = inet_request_mark(sk, skb);
+
+ if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
+ np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
+ np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
+ refcount_inc(&skb->users);
+ ireq->pktopts = skb;
+ }
+ ireq->ir_iif = sk->sk_bound_dev_if;
+
+ /* So that link locals have meaning */
+ if (!sk->sk_bound_dev_if &&
+ ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
+ ireq->ir_iif = inet6_iif(skb);
+
+ /*
+ * Step 3: Process LISTEN state
+ *
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
+ *
+ * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
+ */
+ dreq->dreq_isr = dcb->dccpd_seq;
+ dreq->dreq_gsr = dreq->dreq_isr;
+ dreq->dreq_iss = dccp_v6_init_sequence(skb);
+ dreq->dreq_gss = dreq->dreq_iss;
+ dreq->dreq_service = service;
+
+ if (dccp_v6_send_response(sk, req))
+ goto drop_and_free;
+
+ inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
+ reqsk_put(req);
+ return 0;
+
+drop_and_free:
+ reqsk_free(req);
+drop:
+ __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
+ return -1;
+}
+
+static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
+ struct sk_buff *skb,
+ struct request_sock *req,
+ struct dst_entry *dst,
+ struct request_sock *req_unhash,
+ bool *own_req)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+ struct ipv6_pinfo *newnp;
+ const struct ipv6_pinfo *np = inet6_sk(sk);
+ struct ipv6_txoptions *opt;
+ struct inet_sock *newinet;
+ struct dccp6_sock *newdp6;
+ struct sock *newsk;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ /*
+ * v6 mapped
+ */
+ newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
+ req_unhash, own_req);
+ if (newsk == NULL)
+ return NULL;
+
+ newdp6 = (struct dccp6_sock *)newsk;
+ newinet = inet_sk(newsk);
+ newinet->pinet6 = &newdp6->inet6;
+ newnp = inet6_sk(newsk);
+
+ memcpy(newnp, np, sizeof(struct ipv6_pinfo));
+
+ newnp->saddr = newsk->sk_v6_rcv_saddr;
+
+ inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
+ newsk->sk_backlog_rcv = dccp_v4_do_rcv;
+ newnp->pktoptions = NULL;
+ newnp->opt = NULL;
+ newnp->ipv6_mc_list = NULL;
+ newnp->ipv6_ac_list = NULL;
+ newnp->ipv6_fl_list = NULL;
+ newnp->mcast_oif = inet6_iif(skb);
+ newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+
+ /*
+ * No need to charge this sock to the relevant IPv6 refcnt debug socks count
+ * here, dccp_create_openreq_child now does this for us, see the comment in
+ * that function for the gory details. -acme
+ */
+
+ /* It is tricky place. Until this moment IPv4 tcp
+ worked with IPv6 icsk.icsk_af_ops.
+ Sync it now.
+ */
+ dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
+
+ return newsk;
+ }
+
+
+ if (sk_acceptq_is_full(sk))
+ goto out_overflow;
+
+ if (!dst) {
+ struct flowi6 fl6;
+
+ dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
+ if (!dst)
+ goto out;
+ }
+
+ newsk = dccp_create_openreq_child(sk, req, skb);
+ if (newsk == NULL)
+ goto out_nonewsk;
+
+ /*
+ * No need to charge this sock to the relevant IPv6 refcnt debug socks
+ * count here, dccp_create_openreq_child now does this for us, see the
+ * comment in that function for the gory details. -acme
+ */
+
+ ip6_dst_store(newsk, dst, NULL, NULL);
+ newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
+ NETIF_F_TSO);
+ newdp6 = (struct dccp6_sock *)newsk;
+ newinet = inet_sk(newsk);
+ newinet->pinet6 = &newdp6->inet6;
+ newnp = inet6_sk(newsk);
+
+ memcpy(newnp, np, sizeof(struct ipv6_pinfo));
+
+ newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
+ newnp->saddr = ireq->ir_v6_loc_addr;
+ newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
+ newsk->sk_bound_dev_if = ireq->ir_iif;
+
+ /* Now IPv6 options...
+
+ First: no IPv4 options.
+ */
+ newinet->inet_opt = NULL;
+
+ /* Clone RX bits */
+ newnp->rxopt.all = np->rxopt.all;
+
+ newnp->ipv6_mc_list = NULL;
+ newnp->ipv6_ac_list = NULL;
+ newnp->ipv6_fl_list = NULL;
+ newnp->pktoptions = NULL;
+ newnp->opt = NULL;
+ newnp->mcast_oif = inet6_iif(skb);
+ newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+
+ /*
+ * Clone native IPv6 options from listening socket (if any)
+ *
+ * Yes, keeping reference count would be much more clever, but we make
+ * one more one thing there: reattach optmem to newsk.
+ */
+ opt = ireq->ipv6_opt;
+ if (!opt)
+ opt = rcu_dereference(np->opt);
+ if (opt) {
+ opt = ipv6_dup_options(newsk, opt);
+ RCU_INIT_POINTER(newnp->opt, opt);
+ }
+ inet_csk(newsk)->icsk_ext_hdr_len = 0;
+ if (opt)
+ inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
+ opt->opt_flen;
+
+ dccp_sync_mss(newsk, dst_mtu(dst));
+
+ newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
+ newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
+
+ if (__inet_inherit_port(sk, newsk) < 0) {
+ inet_csk_prepare_forced_close(newsk);
+ dccp_done(newsk);
+ goto out;
+ }
+ *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
+ /* Clone pktoptions received with SYN, if we own the req */
+ if (*own_req && ireq->pktopts) {
+ newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
+ consume_skb(ireq->pktopts);
+ ireq->pktopts = NULL;
+ if (newnp->pktoptions)
+ skb_set_owner_r(newnp->pktoptions, newsk);
+ }
+
+ return newsk;
+
+out_overflow:
+ __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+out_nonewsk:
+ dst_release(dst);
+out:
+ __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
+ return NULL;
+}
+
+/* The socket must have it's spinlock held when we get
+ * here.
+ *
+ * We have a potential double-lock case here, so even when
+ * doing backlog processing we use the BH locking scheme.
+ * This is because we cannot sleep with the original spinlock
+ * held.
+ */
+static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct sk_buff *opt_skb = NULL;
+
+ /* Imagine: socket is IPv6. IPv4 packet arrives,
+ goes to IPv4 receive handler and backlogged.
+ From backlog it always goes here. Kerboom...
+ Fortunately, dccp_rcv_established and rcv_established
+ handle them correctly, but it is not case with
+ dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
+ */
+
+ if (skb->protocol == htons(ETH_P_IP))
+ return dccp_v4_do_rcv(sk, skb);
+
+ if (sk_filter(sk, skb))
+ goto discard;
+
+ /*
+ * socket locking is here for SMP purposes as backlog rcv is currently
+ * called with bh processing disabled.
+ */
+
+ /* Do Stevens' IPV6_PKTOPTIONS.
+
+ Yes, guys, it is the only place in our code, where we
+ may make it not affecting IPv4.
+ The rest of code is protocol independent,
+ and I do not like idea to uglify IPv4.
+
+ Actually, all the idea behind IPV6_PKTOPTIONS
+ looks not very well thought. For now we latch
+ options, received in the last packet, enqueued
+ by tcp. Feel free to propose better solution.
+ --ANK (980728)
+ */
+ if (np->rxopt.all)
+ opt_skb = skb_clone(skb, GFP_ATOMIC);
+
+ if (sk->sk_state == DCCP_OPEN) { /* Fast path */
+ if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
+ goto reset;
+ if (opt_skb)
+ goto ipv6_pktoptions;
+ return 0;
+ }
+
+ /*
+ * Step 3: Process LISTEN state
+ * If S.state == LISTEN,
+ * If P.type == Request or P contains a valid Init Cookie option,
+ * (* Must scan the packet's options to check for Init
+ * Cookies. Only Init Cookies are processed here,
+ * however; other options are processed in Step 8. This
+ * scan need only be performed if the endpoint uses Init
+ * Cookies *)
+ * (* Generate a new socket and switch to that socket *)
+ * Set S := new socket for this port pair
+ * S.state = RESPOND
+ * Choose S.ISS (initial seqno) or set from Init Cookies
+ * Initialize S.GAR := S.ISS
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
+ * Continue with S.state == RESPOND
+ * (* A Response packet will be generated in Step 11 *)
+ * Otherwise,
+ * Generate Reset(No Connection) unless P.type == Reset
+ * Drop packet and return
+ *
+ * NOTE: the check for the packet types is done in
+ * dccp_rcv_state_process
+ */
+
+ if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
+ goto reset;
+ if (opt_skb)
+ goto ipv6_pktoptions;
+ return 0;
+
+reset:
+ dccp_v6_ctl_send_reset(sk, skb);
+discard:
+ if (opt_skb != NULL)
+ __kfree_skb(opt_skb);
+ kfree_skb(skb);
+ return 0;
+
+/* Handling IPV6_PKTOPTIONS skb the similar
+ * way it's done for net/ipv6/tcp_ipv6.c
+ */
+ipv6_pktoptions:
+ if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
+ if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
+ np->mcast_oif = inet6_iif(opt_skb);
+ if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
+ np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
+ if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
+ np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
+ if (np->repflow)
+ np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
+ if (ipv6_opt_accepted(sk, opt_skb,
+ &DCCP_SKB_CB(opt_skb)->header.h6)) {
+ skb_set_owner_r(opt_skb, sk);
+ memmove(IP6CB(opt_skb),
+ &DCCP_SKB_CB(opt_skb)->header.h6,
+ sizeof(struct inet6_skb_parm));
+ opt_skb = xchg(&np->pktoptions, opt_skb);
+ } else {
+ __kfree_skb(opt_skb);
+ opt_skb = xchg(&np->pktoptions, NULL);
+ }
+ }
+
+ kfree_skb(opt_skb);
+ return 0;
+}
+
+static int dccp_v6_rcv(struct sk_buff *skb)
+{
+ const struct dccp_hdr *dh;
+ bool refcounted;
+ struct sock *sk;
+ int min_cov;
+
+ /* Step 1: Check header basics */
+
+ if (dccp_invalid_packet(skb))
+ goto discard_it;
+
+ /* Step 1: If header checksum is incorrect, drop packet and return. */
+ if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr)) {
+ DCCP_WARN("dropped packet with invalid checksum\n");
+ goto discard_it;
+ }
+
+ dh = dccp_hdr(skb);
+
+ DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
+ DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
+
+ if (dccp_packet_without_ack(skb))
+ DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
+ else
+ DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
+
+lookup:
+ sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
+ dh->dccph_sport, dh->dccph_dport,
+ inet6_iif(skb), 0, &refcounted);
+ if (!sk) {
+ dccp_pr_debug("failed to look up flow ID in table and "
+ "get corresponding socket\n");
+ goto no_dccp_socket;
+ }
+
+ /*
+ * Step 2:
+ * ... or S.state == TIMEWAIT,
+ * Generate Reset(No Connection) unless P.type == Reset
+ * Drop packet and return
+ */
+ if (sk->sk_state == DCCP_TIME_WAIT) {
+ dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
+ inet_twsk_put(inet_twsk(sk));
+ goto no_dccp_socket;
+ }
+
+ if (sk->sk_state == DCCP_NEW_SYN_RECV) {
+ struct request_sock *req = inet_reqsk(sk);
+ struct sock *nsk;
+
+ sk = req->rsk_listener;
+ if (unlikely(sk->sk_state != DCCP_LISTEN)) {
+ inet_csk_reqsk_queue_drop_and_put(sk, req);
+ goto lookup;
+ }
+ sock_hold(sk);
+ refcounted = true;
+ nsk = dccp_check_req(sk, skb, req);
+ if (!nsk) {
+ reqsk_put(req);
+ goto discard_and_relse;
+ }
+ if (nsk == sk) {
+ reqsk_put(req);
+ } else if (dccp_child_process(sk, nsk, skb)) {
+ dccp_v6_ctl_send_reset(sk, skb);
+ goto discard_and_relse;
+ } else {
+ sock_put(sk);
+ return 0;
+ }
+ }
+ /*
+ * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
+ * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+ * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+ */
+ min_cov = dccp_sk(sk)->dccps_pcrlen;
+ if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
+ dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
+ dh->dccph_cscov, min_cov);
+ /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
+ goto discard_and_relse;
+ }
+
+ if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
+ goto discard_and_relse;
+
+ return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
+ refcounted) ? -1 : 0;
+
+no_dccp_socket:
+ if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
+ goto discard_it;
+ /*
+ * Step 2:
+ * If no socket ...
+ * Generate Reset(No Connection) unless P.type == Reset
+ * Drop packet and return
+ */
+ if (dh->dccph_type != DCCP_PKT_RESET) {
+ DCCP_SKB_CB(skb)->dccpd_reset_code =
+ DCCP_RESET_CODE_NO_CONNECTION;
+ dccp_v6_ctl_send_reset(sk, skb);
+ }
+
+discard_it:
+ kfree_skb(skb);
+ return 0;
+
+discard_and_relse:
+ if (refcounted)
+ sock_put(sk);
+ goto discard_it;
+}
+
+static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
+ int addr_len)
+{
+ struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct inet_sock *inet = inet_sk(sk);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct in6_addr *saddr = NULL, *final_p, final;
+ struct ipv6_txoptions *opt;
+ struct flowi6 fl6;
+ struct dst_entry *dst;
+ int addr_type;
+ int err;
+
+ dp->dccps_role = DCCP_ROLE_CLIENT;
+
+ if (addr_len < SIN6_LEN_RFC2133)
+ return -EINVAL;
+
+ if (usin->sin6_family != AF_INET6)
+ return -EAFNOSUPPORT;
+
+ memset(&fl6, 0, sizeof(fl6));
+
+ if (np->sndflow) {
+ fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
+ IP6_ECN_flow_init(fl6.flowlabel);
+ if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
+ struct ip6_flowlabel *flowlabel;
+ flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
+ if (flowlabel == NULL)
+ return -EINVAL;
+ fl6_sock_release(flowlabel);
+ }
+ }
+ /*
+ * connect() to INADDR_ANY means loopback (BSD'ism).
+ */
+ if (ipv6_addr_any(&usin->sin6_addr))
+ usin->sin6_addr.s6_addr[15] = 1;
+
+ addr_type = ipv6_addr_type(&usin->sin6_addr);
+
+ if (addr_type & IPV6_ADDR_MULTICAST)
+ return -ENETUNREACH;
+
+ if (addr_type & IPV6_ADDR_LINKLOCAL) {
+ if (addr_len >= sizeof(struct sockaddr_in6) &&
+ usin->sin6_scope_id) {
+ /* If interface is set while binding, indices
+ * must coincide.
+ */
+ if (sk->sk_bound_dev_if &&
+ sk->sk_bound_dev_if != usin->sin6_scope_id)
+ return -EINVAL;
+
+ sk->sk_bound_dev_if = usin->sin6_scope_id;
+ }
+
+ /* Connect to link-local address requires an interface */
+ if (!sk->sk_bound_dev_if)
+ return -EINVAL;
+ }
+
+ sk->sk_v6_daddr = usin->sin6_addr;
+ np->flow_label = fl6.flowlabel;
+
+ /*
+ * DCCP over IPv4
+ */
+ if (addr_type == IPV6_ADDR_MAPPED) {
+ u32 exthdrlen = icsk->icsk_ext_hdr_len;
+ struct sockaddr_in sin;
+
+ SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
+
+ if (__ipv6_only_sock(sk))
+ return -ENETUNREACH;
+
+ sin.sin_family = AF_INET;
+ sin.sin_port = usin->sin6_port;
+ sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
+
+ icsk->icsk_af_ops = &dccp_ipv6_mapped;
+ sk->sk_backlog_rcv = dccp_v4_do_rcv;
+
+ err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
+ if (err) {
+ icsk->icsk_ext_hdr_len = exthdrlen;
+ icsk->icsk_af_ops = &dccp_ipv6_af_ops;
+ sk->sk_backlog_rcv = dccp_v6_do_rcv;
+ goto failure;
+ }
+ np->saddr = sk->sk_v6_rcv_saddr;
+ return err;
+ }
+
+ if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+ saddr = &sk->sk_v6_rcv_saddr;
+
+ fl6.flowi6_proto = IPPROTO_DCCP;
+ fl6.daddr = sk->sk_v6_daddr;
+ fl6.saddr = saddr ? *saddr : np->saddr;
+ fl6.flowi6_oif = sk->sk_bound_dev_if;
+ fl6.fl6_dport = usin->sin6_port;
+ fl6.fl6_sport = inet->inet_sport;
+ security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
+
+ opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
+ final_p = fl6_update_dst(&fl6, opt, &final);
+
+ dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
+ if (IS_ERR(dst)) {
+ err = PTR_ERR(dst);
+ goto failure;
+ }
+
+ if (saddr == NULL) {
+ saddr = &fl6.saddr;
+ sk->sk_v6_rcv_saddr = *saddr;
+ }
+
+ /* set the source address */
+ np->saddr = *saddr;
+ inet->inet_rcv_saddr = LOOPBACK4_IPV6;
+
+ ip6_dst_store(sk, dst, NULL, NULL);
+
+ icsk->icsk_ext_hdr_len = 0;
+ if (opt)
+ icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
+
+ inet->inet_dport = usin->sin6_port;
+
+ dccp_set_state(sk, DCCP_REQUESTING);
+ err = inet6_hash_connect(&dccp_death_row, sk);
+ if (err)
+ goto late_failure;
+
+ dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
+ sk->sk_v6_daddr.s6_addr32,
+ inet->inet_sport,
+ inet->inet_dport);
+ err = dccp_connect(sk);
+ if (err)
+ goto late_failure;
+
+ return 0;
+
+late_failure:
+ dccp_set_state(sk, DCCP_CLOSED);
+ __sk_dst_reset(sk);
+failure:
+ inet->inet_dport = 0;
+ sk->sk_route_caps = 0;
+ return err;
+}
+
+static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
+ .queue_xmit = inet6_csk_xmit,
+ .send_check = dccp_v6_send_check,
+ .rebuild_header = inet6_sk_rebuild_header,
+ .conn_request = dccp_v6_conn_request,
+ .syn_recv_sock = dccp_v6_request_recv_sock,
+ .net_header_len = sizeof(struct ipv6hdr),
+ .setsockopt = ipv6_setsockopt,
+ .getsockopt = ipv6_getsockopt,
+ .addr2sockaddr = inet6_csk_addr2sockaddr,
+ .sockaddr_len = sizeof(struct sockaddr_in6),
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_ipv6_setsockopt,
+ .compat_getsockopt = compat_ipv6_getsockopt,
+#endif
+};
+
+/*
+ * DCCP over IPv4 via INET6 API
+ */
+static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
+ .queue_xmit = ip_queue_xmit,
+ .send_check = dccp_v4_send_check,
+ .rebuild_header = inet_sk_rebuild_header,
+ .conn_request = dccp_v6_conn_request,
+ .syn_recv_sock = dccp_v6_request_recv_sock,
+ .net_header_len = sizeof(struct iphdr),
+ .setsockopt = ipv6_setsockopt,
+ .getsockopt = ipv6_getsockopt,
+ .addr2sockaddr = inet6_csk_addr2sockaddr,
+ .sockaddr_len = sizeof(struct sockaddr_in6),
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_ipv6_setsockopt,
+ .compat_getsockopt = compat_ipv6_getsockopt,
+#endif
+};
+
+/* NOTE: A lot of things set to zero explicitly by call to
+ * sk_alloc() so need not be done here.
+ */
+static int dccp_v6_init_sock(struct sock *sk)
+{
+ static __u8 dccp_v6_ctl_sock_initialized;
+ int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
+
+ if (err == 0) {
+ if (unlikely(!dccp_v6_ctl_sock_initialized))
+ dccp_v6_ctl_sock_initialized = 1;
+ inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
+ }
+
+ return err;
+}
+
+static void dccp_v6_destroy_sock(struct sock *sk)
+{
+ dccp_destroy_sock(sk);
+ inet6_destroy_sock(sk);
+}
+
+static struct timewait_sock_ops dccp6_timewait_sock_ops = {
+ .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
+};
+
+static struct proto dccp_v6_prot = {
+ .name = "DCCPv6",
+ .owner = THIS_MODULE,
+ .close = dccp_close,
+ .connect = dccp_v6_connect,
+ .disconnect = dccp_disconnect,
+ .ioctl = dccp_ioctl,
+ .init = dccp_v6_init_sock,
+ .setsockopt = dccp_setsockopt,
+ .getsockopt = dccp_getsockopt,
+ .sendmsg = dccp_sendmsg,
+ .recvmsg = dccp_recvmsg,
+ .backlog_rcv = dccp_v6_do_rcv,
+ .hash = inet6_hash,
+ .unhash = inet_unhash,
+ .accept = inet_csk_accept,
+ .get_port = inet_csk_get_port,
+ .shutdown = dccp_shutdown,
+ .destroy = dccp_v6_destroy_sock,
+ .orphan_count = &dccp_orphan_count,
+ .max_header = MAX_DCCP_HEADER,
+ .obj_size = sizeof(struct dccp6_sock),
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
+ .rsk_prot = &dccp6_request_sock_ops,
+ .twsk_prot = &dccp6_timewait_sock_ops,
+ .h.hashinfo = &dccp_hashinfo,
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_dccp_setsockopt,
+ .compat_getsockopt = compat_dccp_getsockopt,
+#endif
+};
+
+static const struct inet6_protocol dccp_v6_protocol = {
+ .handler = dccp_v6_rcv,
+ .err_handler = dccp_v6_err,
+ .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
+};
+
+static const struct proto_ops inet6_dccp_ops = {
+ .family = PF_INET6,
+ .owner = THIS_MODULE,
+ .release = inet6_release,
+ .bind = inet6_bind,
+ .connect = inet_stream_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = inet_accept,
+ .getname = inet6_getname,
+ .poll = dccp_poll,
+ .ioctl = inet6_ioctl,
+ .listen = inet_dccp_listen,
+ .shutdown = inet_shutdown,
+ .setsockopt = sock_common_setsockopt,
+ .getsockopt = sock_common_getsockopt,
+ .sendmsg = inet_sendmsg,
+ .recvmsg = sock_common_recvmsg,
+ .mmap = sock_no_mmap,
+ .sendpage = sock_no_sendpage,
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_sock_common_setsockopt,
+ .compat_getsockopt = compat_sock_common_getsockopt,
+#endif
+};
+
+static struct inet_protosw dccp_v6_protosw = {
+ .type = SOCK_DCCP,
+ .protocol = IPPROTO_DCCP,
+ .prot = &dccp_v6_prot,
+ .ops = &inet6_dccp_ops,
+ .flags = INET_PROTOSW_ICSK,
+};
+
+static int __net_init dccp_v6_init_net(struct net *net)
+{
+ if (dccp_hashinfo.bhash == NULL)
+ return -ESOCKTNOSUPPORT;
+
+ return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
+ SOCK_DCCP, IPPROTO_DCCP, net);
+}
+
+static void __net_exit dccp_v6_exit_net(struct net *net)
+{
+ inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
+}
+
+static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
+{
+ inet_twsk_purge(&dccp_hashinfo, AF_INET6);
+}
+
+static struct pernet_operations dccp_v6_ops = {
+ .init = dccp_v6_init_net,
+ .exit = dccp_v6_exit_net,
+ .exit_batch = dccp_v6_exit_batch,
+};
+
+static int __init dccp_v6_init(void)
+{
+ int err = proto_register(&dccp_v6_prot, 1);
+
+ if (err)
+ goto out;
+
+ inet6_register_protosw(&dccp_v6_protosw);
+
+ err = register_pernet_subsys(&dccp_v6_ops);
+ if (err)
+ goto out_destroy_ctl_sock;
+
+ err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
+ if (err)
+ goto out_unregister_proto;
+
+out:
+ return err;
+out_unregister_proto:
+ unregister_pernet_subsys(&dccp_v6_ops);
+out_destroy_ctl_sock:
+ inet6_unregister_protosw(&dccp_v6_protosw);
+ proto_unregister(&dccp_v6_prot);
+ goto out;
+}
+
+static void __exit dccp_v6_exit(void)
+{
+ inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
+ unregister_pernet_subsys(&dccp_v6_ops);
+ inet6_unregister_protosw(&dccp_v6_protosw);
+ proto_unregister(&dccp_v6_prot);
+}
+
+module_init(dccp_v6_init);
+module_exit(dccp_v6_exit);
+
+/*
+ * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
+ * values directly, Also cover the case where the protocol is not specified,
+ * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
+ */
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
+MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");